title: Poly-L-lactic acid - hydroxyapatite (PLLA-HA) bioabsorbable interference screws for tibial graft fixation in anterior cruciate ligament (ACL) reconstruction surgery: MR evaluation of osteointegration and degradation features.
abstract: OBJECTIVE
  We evaluated with magnetic resonance imaging (MRI) the degradation and osteointegration features of a new type of bioabsorbable interference (BioRCI) screw composed of poly-L-lactic acid and hydroxyapatite (PLLA-HA) used for tibial graft fixation in anterior cruciate ligament (ACL) reconstruction.
  
  
  METHODS
  Thirty-one patients underwent arthroscopic surgery for ACL reconstruction using doubled gracilis and semitendinosus tendons fixed to the tibial tunnel with PLLA-HA (BioRCI-HA) screws. Two groups of patients were evaluated, one group 10-13 months after surgery and the other after 30-40 months. The standard knee ligament evaluation form of the International Knee Documentation Committee (IKDC) was used for clinical assessment and MRI for the radiological assessment.
  
  
  RESULTS
  MRI after 10-13 months revealed findings referable to healing and integration of the bone-graft-screw system, findings that disappeared at later follow-up examinations. The BioRCI-HA screw remained constantly visible in all patients, although with changes in signal intensity over time.
  
  
  CONCLUSIONS
  BioRCI-HA screws allow adequate primary stability and superior osteoconduction and biocompatibility in comparison with plain PLLA screws. The absence of ferromagnetic artefacts allows accurate MRI follow-up and adequate evaluation of ligament synovialisation, screw degradation and graft osteointegration.
authors.affiliation: Università degli Studi di Foggia, Radiodiagnostica Universitaria, Viale L. Pinto 1, 70100 Foggia, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Macarini
authors.forename: P
authors.initials: P
authors.lastname: Milillo
authors.forename: A
authors.initials: A
authors.lastname: Mocci
authors.forename: R
authors.initials: R
authors.lastname: Vinci
authors.forename: G C
authors.initials: GC
authors.lastname: Ettorre
mesh_terms: D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D001182:Arthroscopy; D001863:Bone Screws; D017886:Durapatite; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods; D016348:Osseointegration; D011091:Polyesters; D013977:Tibia / Q000637:transplantation*; D055815:Young Adult
chemical_list: D011091:Polyesters; C499699:hydroxyapatite-polylactide; D017886:Durapatite